WHILST a heat of 140° F. (60° C.) appears to be 
destructive to Bacteria, Vibriones, and __ their 
supposed germs ina neutral saline solution, a heat 
of 149° or of 158°F. is often necessary to prevent 
the occurrence of putrefaction in the inoculated 
fluids when specimens of organic infusicns are 
employed. What is the reason of this difference ? 
Is it owing to the fact that living organisms are 
enabled to withstand the destructive influence of 
heat better in such fluids than when immersed in 
neutral saline solutions? At first sight it might 
seem that this was the conclusion to be drawn 
We must not, however, rest satisfied with mere 
superficial considerations. 
The problem is an interesting one; yet it should 
be clearly understood that its solution, whatever it 
may be, cannot in the least affect the validity of 
the conclusion arrived at in my last paper, viz. 
' ‘that living matter is certainly capable of arising 
de novo. We were enabled to arrive at the con- 
